A velocity vs. time graph for an object is shown.


Which best describes the acceleration of the object?

constant and positive
constant and negative
changing and positive
changing and negative

Here refrigerator removes 55 kcal heat from freezer

Refrigerator releases 73.5 kcal heat to surrounding

So here we can use energy conservation principle by II Law of thermodynamics

the law says that

[tex]Q_1 = Q_2 + W[/tex]

here we know that

[tex]Q_1[/tex] = heat released to the surrounding

[tex]Q_2[/tex] = heat absorbed from freezer

W = work done by the compressor

now using above equation we can write

[tex]73.5 = 55 + W[/tex]

[tex]W = 73.5 - 55[/tex]

[tex]W = 18.5 kcal[/tex]

So here compressor has to do 18.5 k cal work on it

Final answer:

The work done by the refrigerator's compressor, when it removes 55.0 kcal of heat from the freezer and releases 73.5 kcal through the condenser, is calculated to be 77,464 joules, after converting kcal to joules.

Explanation:

To determine the work done by the compressor in a refrigerator when it removes 55.0 kcal of heat from the freezer and releases 73.5 kcal through the condenser on the back, we can use the principle of conservation of energy. According to the first law of thermodynamics, the energy extracted from the freezer plus the work done by the compressor equals the energy released into the environment through the condenser.

The work done by the compressor (W) can be calculated by subtracting the heat removed from the cold reservoir (Qc) from the heat added to the hot reservoir (Qh).

First, we need to convert the heat quantities from kcal to joules because the standard unit of energy in physics is the joule (J). 1 kcal = 4184 J, therefore:

Qc = 55.0 kcal * 4184 J/kcal = 230120 J

Qh = 73.5 kcal * 4184 J/kcal = 307584 J

Now, calculate the work done:

W = Qh - Qc = 307584 J - 230120 J = 77464 J

Therefore, the compressor performed 77464 J of work in this process.

Gravity is the force that causes acceleration. Friction is a force that opposes motion, energy is a capacity to do work, and velocity is a measure of speed in a specific direction.

Of the forces listed in your question, it is the force of gravity that causes acceleration. For example, when an object is dropped, it accelerates toward Earth under this force. This is popularly known as the force of gravity and represented as 'g'. The rate of acceleration due to gravity on Earth is approximately 9.81 m/s². Friction, on the other hand, actually opposes motion and may cause deceleration, if it is the only force acting on an object. Energy is a capacity to do work and does not directly cause acceleration, while velocity is a measure of speed in a specific direction and is a result, not a cause, of acceleration.

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Answer:

Option (1).

Explanation:

Precipitation reaction may be defined as the chemical reaction in which an insoluble substance called precipitate formed at the end of reaction. The ions are displaced twice during the precipitation reaction.

The mixing of two clear liquids forms a white substance. This substance is an insoluble precipitate that forms by the chemical combination of the reactants. The two reactants has undergone the chemical change that leads to the formation of precipitate.

Thus, the correct answer is option (1).

The student can conclude that a chemical change occurred and a precipitate was produced.

The student can conclude that the two liquids have gone through a chemical change in which a new substance called a precipitate was produced. When two clear liquids are mixed and a white powdery solid settles on the bottom, it indicates the formation of a precipitate. This is a clear indication of a chemical reaction taking place between the two liquids.

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vector A has magnitude 12 m and direction +y

so we can say

[tex]\vec A = 12 \hat j[/tex]

vector B has magnitude 33 m and direction - x

[tex]\vec B = -33 \hat i[/tex]

Now the resultant of vector A and B is given as

[tex]\vec A + \vec B = 12 \hat j - 33 \hat i[/tex]

now for direction of the two vectors resultant will be given as

[tex]\theta = tan^{-1}\frac{12}{-33}[/tex]

[tex]\theta = 160 degree[/tex]

so it is inclined at 160 degree counterclockwise from + x axis

magnitude of A and B will be

[tex]R = \sqrt{A^2 + B^2}[/tex]

[tex]R = \sqrt{12^2 + 33^2} = 35.11 m[/tex]

so magnitude will be 35.11 m

Final answer:

The direction of the resultant vector A› + B› is 20.1° north of the negative x-axis, and its magnitude is approximately 35.1 m.

Explanation:

To find the direction and magnitude of the resultant vector A› + B›, we can use vector addition. Vector A› points in the positive y direction and has a magnitude of 12 m, so its components are (0, 12). Vector B› has a magnitude of 33 m and points in the negative x direction, with components (-33, 0). By adding these components, we get the resultant vector R = A + B = (0 - 33, 12 + 0) = (-33, 12).

To find the magnitude of the resultant vector, we use the Pythagorean theorem:

|R| = √((-33)^2 + (12)^2) = √(1089 + 144) = √(1233) ≈ 35.1 m

The direction of resultant vector R can be found by calculating its angle θ with respect to the negative x-axis (since the x component is negative) using the tangent function:

θ = arctan(|12| / |-33|) = arctan(12 / 33) ≈ 20.1°

The direction is therefore 20.1° above (north of) the negative x-axis.

Answer:

No, its not reasonable.

Explanation:

The substance that is to be dissolved is known as solute. The substance that is dissolving is known as solvent.

The amount of solvent  in the mixture should be greater than that of solute.

Suppose we are taking a solvent in a beaker and we are continuously adding solute in it. Initially the solute dissolve quickly. At some point the solute stops dissolving in the solvent. This is known as saturation point of the solvent. After saturation point if solute is added further it does not dissolve in the solvent.

So, its not possible to dissolve 12.8 g of one substance in 11 g of another.

F = ma

=   70kg ×  5ms⁻²

F =350N  

The sprinter is exerting a force of 350 Newtons.

The force exerted by the sprinter can be calculated using Newton's second law, which states that force is equal to mass multiplied by acceleration. In this case, the sprinter's mass is 70 kg and the acceleration is 5 m/s². So, the force exerted by the sprinter is:

Force = mass x acceleration

Force = 70 kg x 5 m/s²

Force = 350 N

Therefore, the sprinter is exerting a force of 350 Newtons.

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As per the question the total distance is given as 4 km.

We are asked to calculate the average speed.

The time taken by the body to travel each kilometre are 5.9 min,6.2 min.,6.3min. and 6 min. respectively.

The average speed of a body is defined as the ratio of total distance travelled by the body to the total time.

Mathematically the average speed is written as _

V= Total distance/Total time

i.e V = S/T

Where S is the total distance travelled and T is the total time

Here total distance (S)= 4 km

The total time T= (5.9+6.2 +6.3+ 6.0 )minutes

=24.4 min.

Hence average speed V = 4 km/24.4 min

= 0.16 km/min.

Hence the correct option is A .

The average speed of the runner for the race is approximately 0.16km/min.

Option A) 0.16km/min is the correct answer.

Given the data in the question;

First we calculate the total time spent in the race by the runner.

Total time;

[tex]t_{total} = t_1 + t_2 + t_3 + t_4\\\\t_{total} = 5.9min + 6.2min + 6.3min + 6.0min\\\\t_{total} = 24.4min[/tex]

Next, we determine the average speed.

Speed is the distance traveled per unit of time

That is; Speed = Distance / Time

[tex]s = \frac{d}{t}[/tex]

Hence, In this case, [tex]s = \frac{d}{t_{total}}[/tex]

We substitute our values into the equation

[tex]s = \frac{4.0km}{24.4min}\\\\s = 0.16km/min[/tex]

Therefore, the average speed of the runner for the race is approximately 0.16km/min.

Option A) 0.16km/min is the correct answer.

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by superposition method we can find current in R5

here first let say only 2V battery is present in the circuit

now the equivalent resistance to be found for which we can say

2.2 k ohm and 1 k ohm is connected in parallel

[tex]r_1 = \frac{2.2 * 1}{2.2 + 1}[/tex]

[tex]r_1 = 0.6875 k ohm[/tex]

now it is in series with 1 k ohm and then that part is in parallel with 2.2 k ohm

[tex]r_2 = \frac{2.2* (1+0.6875)}{2.2 + (1+0.6875)}[/tex]

[tex]r_2 = 0.95 k ohm[/tex]

now the current flowing through the battery is

[tex]i = \frac{2}{1 + 0.95} = 1.02 mA[/tex]

now this will divide into R3 and R2 so current flowing in R3 will be

[tex]i_1 = \frac{2.2}{2.2+1.6875}*1.02 = 0.58 mA[/tex]

now this will again divide in R4 and R5

so current in R5 will be

[tex]i_5 = \frac{R_4}{R_4 + R_5}* i_1 [/tex]

[tex]i_5 = 0.18 mA[/tex]

now when only 3 V battery is present in the circuit

R1 and R2 is in parallel and then it is in series with R3

so parallel combination will be

[tex]r_1 = \frac{1*2.2}{2.2 +1} = 0.6875k ohm[/tex]

also after its series with R3

[tex]r_2 = 1 + 0.6875 = 1.6875 k ohm[/tex]

now it is in parallel with R5 on other side

[tex]r_3 = \frac{1.6875 * 2.2}{1.6875 + 2.2} = 0.95 k ohm[/tex]

now current through the battery will be given as

[tex]i = \frac{3}{1 + 0.95} = 1.53 mA[/tex]

now it is divide in r2 and R5

so current in R5 is given as

[tex]i_5 = \frac{r_2}{r_2 + R_5}*i[/tex]

[tex]i_5 = \frac{1.6875}{2.2 + 1.6875} * 1.53[/tex]

[tex]i_5 = 0.67 mA[/tex]

now the total current in R5 will be given by super position which is

[tex]i = 0.67 + 0.18 = 0.85 mA[/tex]

so there is 0.85 mA current through R5 resistance

Answer:

The answer is 0.39 m/s ²

Explanation:

Since the box moves with steady speed,  

Friction=force in even direction=260*Cos20=244.3N  

Ordinary force=mg+FSinθ=1089N  

μN=f  

μ=244.3/1089=0.224  

N=mg-FSinθ=911.1N  

a=(260 Cos20-0.224*911.1)/(1000/9.8)=0.39m/s²

Agriculture

and

botany

Horticulture is the most useful field of study for someone wanting to grow safe food crops. It involves applying knowledge of genetics and plant physiology, understanding environmental factors and their impact on plant growth, and incorporating sustainable agricultural practices.

The field of study that would be most useful for a person who wants to grow safe food crops is Horticulture.

Horticulturists improve crops by applying their knowledge of genetics and plant physiology. This career has been revolutionized by progress made in understanding how environmental factors affect plant growth and development. They take classes in botany, plant physiology, plant pathology, landscape design, and plant breeding. Furthermore, the success of crops is largely dependent on soil quality, which houses a diversity of organisms that maintain nutrient cycles and soil texture. These processes are known as ecosystem services.

To successfully cultivate plants, growers must possess a deep understanding of soil, environmental conditions, and their impact on different plant varieties. Future food production also must be transformed into systems that are environmentally sound and economically affordable, underscoring the relevance of sustainable agricultural practices in Horticulture.

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Answer:

Nickel - Transitional Metal

Potassium- Alkali Metal

Cadmium- Transitional Metal

Calcium- Alkaline Earth Metal

Barium- Alkaline Earth Metal

Explanation:

Answer:

Nickel - Transitional Metal

Potassium- Alkali Metal

Cadmium- Transitional Metal

Calcium- Alkaline Earth Metal

Barium- Alkaline Earth Metal

Explanation:

The correct answers are:

- is repulsive

- produces light

- produces electricity

Explanation:

The electromagnetic force can be either attractive (when the two charges have opposite sign) or repulsive (when the two charges have same sign). On the contrary, the gravitational attraction is always attractive, so "is repulsive" is a property of the electromagnetic force only.

Moreover, as a result of electromagnetic interactions, photons can be produced (so, light, since light consists of photons), as well as electrons or other charged particles (so, electricity, since electrical currents consists of electrons or charged particles), while the gravitational force is not able to produce light or electrical currents.

If Val is comparing the gravitational force and the electromagnetic force, what applies is:

Electric and Magnetic Interaction: The electromagnetic force encompasses both electric and magnetic interactions. It is responsible for electric attraction and repulsion between charged particles and the behavior of magnets.

2. Acts on Charged Particles: The electromagnetic force acts on charged particles, which can be positively charged (protons), negatively charged (electrons), or both. Like charges repel each other, while opposite charges attract.

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dependent volume and mass and independent melting point and bowing point

The two size dependent properties of iron are Volume and Mass and size independent properties are Melting point and Boiling point respectively.

The given problem is based on the properties of iron nail. The iron nails are made of steel and small amount of carbon for increasing the hardness.

The two size dependent properties of iron nails are as follows:

The size independent properties of the iron nails are as follows:

Thus, we can conclude that the two size dependent properties of iron are Volume and Mass and size independent properties are Melting point and Boiling point respectively.

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the force that resists the movement of a solid object through a fluid (liquid or gas). Hope this helps.

Fluid friction, or drag, is the force resisting the motion of an object through a fluid like water or air. It depends on factors such as fluid viscosity, object shape and speed, and contact surface area. Examples include a boat moving through water and air resistance on a falling parachutist.

Fluid friction, also known as drag, is the force that opposes the motion of an object through a fluid (liquid or gas). This type of friction occurs when layers of the fluid move at different speeds or directions. For instance, a boat moving through water experiences fluid friction between the hull and the water, which resists its motion.

Fluid friction is influenced by several factors, including the viscosity of the fluid, the shape and speed of the object, and the surface area in contact with the fluid. An example of this is air resistance, which acts on a parachutist falling through the atmosphere, slowing their descent due to the opposition force of the air.

Speed of Ferry is towards North with magnitude 6.2 m/s

Here if we assume that North direction is along Y axis and East is along X axis then we can say

[tex]\vec v_f = 6.2 \hat j[/tex]

Now a person walk on ferry with speed 1.5 m/s towards east with respect to Ferry

so it is given as

[tex]\vec v_{pf} = 1.5 \hat i[/tex]

also by the concept of relative motion we know that

[tex]\vec v_{pf} = \vec v_p - \vec v_f[/tex]

now plug in all values in it

[tex]1.5 \hat i = \vec v_p - 6.2 \hat j[/tex]

[tex]\vec v_p = 1.5 \hat i + 6.2 \hat j[/tex]

now if we need to find the speed of the person then we need to find its magnitude

so it is given as

[tex]v = \sqrt{1.5^2 + 6.2^2}[/tex]

[tex]v = 6.37 m/s[/tex]

Here's the handy factoid I always carry around in my toolbox:

When the three dimensions of a solid object all change by a factor of ' K ' . . . .

--  the surface area of the object changes by a factor of  K²

-- the volume of the object changes by a factor of  K³ .

So I guess if the surface area increases by 3, that means each linear dimension increased by √3, and the volume has to increase by  (√3)³ .  

That's 5.196 times the dog's original volume.

(And so does his weight.  The poor thing is staggering around wondering what was in that last bowl of kibble that he inhaled.)

The volume of bullbog is increased by a factor 5.2 when its surface area increases by a factor of 3

What is volume ?

Volume is a three dimensional space occupy by the body of particular shape. Generally expressed in cubic meter.

It should be noted that :

A solid object's three dimensions change by a factor of K when all three dimensions change by the same factor, which means its surface area changes by a factor of K², and its volume changes by a factor of K³ when the three dimensions change by the same factor.

It is given that the a small french bulldog grows isometrically which  means that any change in dimension of bulldog will change equally in all direction and surface area of increases by factor 3,

Then the side will increase by a factor of :

k² = 3

k = √3

Now the volume of bulldog will increase by factor of :

k³ = (√3)³

   ≈ 5.2

Therefore, the volume of bullbog is increased by a factor 5.2

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the answer to this question is c

Base on the information that carbon and hydrogen combined chemically to form methane, carbon and hydrogen are elements and methane is a compound

Elements are pure substance that contains only atoms that cannot be decomposed into smaller unit by chemical process.

Therefore, Carbon(C) and Hydrogen(H) are elements because they are pure substance that cannot be decompose by any chemical process.

Compound are formed by chemically bonding two or more chemical elements together. Compounds consist of different kind of elements. Therefore, Carbon and Hydrogen combine to form a compound. This is a combination of two elements namely carbon and hydrogen.

The compound formed from this combination is methane and methane is a compound.

Therefore, carbon and hydrogen are elements and methane is a compound

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Intensity of sunlight at given position is defined as power received per unit area

so here we can say

[tex]I = 2 kJ/s*m^2[/tex]

area  on which photons are received is given as

[tex]A = 4.80 cm^2 = 4.80 * 10^-4 m^2[/tex]

now we can find the power received due to sunlight

[tex]P = I*A[/tex]

[tex]P = 2* 10^3 * 4.80 * 10^-4[/tex]

[tex]P = 0.96 Watt[/tex]

now we can say this power is due to photons that strikes on surface of earth

so here we can say

[tex]P = N\frac{hc}{\lambda}[/tex]

given here that

[tex]\lambda = 510 nm[/tex]

[tex]0.96 = N\frac{6.6 * 10^{-34}* 3 * 10^8}{510*10^{-9}}[/tex]

[tex]0.96 = N * 3.88 * 10^{-19}[/tex]

[tex]N = \frac{0.96}{3.88*10^{-19}}[/tex]

[tex]N = 2.47 * 10^{18}[/tex]

so it will strike 2.47 * 10^18 photons on given area per second

To find the number of photons hitting a 4.80 cm² area per second, you must convert the area to m², calculate the energy per photon using Planck's constant and the speed of light, determine the total energy per second using the given intensity, and divide by the energy per photon. Approximately [tex]2.45 \times 10^{21[/tex] photons hit the area each second.

To calculate how many photons strike a 4.80 cm² area per second when the sunlight intensity is [tex]2.00 kJ \cdot s^{-1} \cdot m^{-2}[/tex] and the average wavelength of photons is 510.0 nm, follow these steps:

Convert the area from cm² to m²: 4.80 cm² = 4.80 × [tex]10^{-4}[/tex] m².

Calculate the energy per photon using the formula E = hc/λ, where h is Planck's constant (6.626 × [tex]10^{-34}[/tex] J·s), c is the speed of light (3.00 × [tex]10^8[/tex] m/s), and λ is the wavelength in meters.

Convert the wavelength from nm to m: 510.0 nm = 510.0 × [tex]10^{-9}[/tex] m.

Calculate the energy per photon: E = (6.626 × [tex]10^{-34}[/tex] J·s × 3.00 × [tex]10^8[/tex] m/s) / (510.0 × [tex]10^{-9}[/tex] m) = ≈ 3.91 × [tex]10^{-19}[/tex] J.

Determine the total energy hitting the area per second: Energy = Intensity x Area = 2.00 kJ/s·m² × 4.80 × [tex]10^{-4}[/tex] m² = 0.96 J/s.

Divide the total energy hitting the area per second by the energy per photon to find the number of photons: Number of photons = 0.96 J/s / 3.91 × [tex]10^{-9}[/tex] J/photon ≈ 2.45 × [tex]10^{21}[/tex] photons/s.

Therefore, approximately 2.45 × [tex]10^{21}[/tex] photons hit a 4.80 cm² area each second on a clear day in Madison, Wisconsin.

A chemical reaction produced a gas. I use to make rockets with baking soda and vinegar. Just put the 2 together and jam a plug in the top and the gas will shoot it into the air.

The statement is true.

mass of the chair = 25 kg

Force required to start the motion = 165 N

Force required to maintain the motion = 127 N

part a)

when we applied the force to just start the motion then it is just equal to the limiting friction force

[tex]F_s = F[/tex]

now as we know that

[tex]\mu_s mg = 165[/tex]

[tex]\mu_s * 25 * 9.8 = 165[/tex]

[tex]\mu_s = \frac{165}{25*9.8}[/tex]

[tex]\mu_s = 0.67[/tex]

PART b)

when object has started motion then to maintain its motion we need external force to balance kinetic friction  

[tex]F_k = F[/tex]

now as we know that

[tex]\mu_k mg = 127[/tex]

[tex]\mu_k * 25 * 9.8 = 127[/tex]

[tex]\mu_k = \frac{127}{25*9.8}[/tex]

[tex]\mu_k = 0.52[/tex]

Since rope is parallel to the inclined plane so here we can say that net force parallel to the person which is pulling upwards must counterbalance the component of weight of the person.

Now here we will do the components of the weight of the person

given that weight of the person = 500 N

now its components are

[tex]W_x = 500 cos37[/tex]

[tex]W_y = 500 sin37[/tex]

now here as we can say that one of the component is balanced here by the normal force perpendicular to plane

while the other component of the weight is balanced by the force applied on the rope

So here the force applied on the rope will be given as

[tex]F = W_y = 500 sin37[/tex]

[tex]F = 300 N[/tex]

so it apply 300 N force along the inclined plane

Aaron's car is moving at speed of 30 m/s

His reaction time is given as 0.7 s

but when he is tired the reaction time is doubled

Now we need to find the distance covered by his car when he is tired during the time when he react to apply brakes

So here since during this time speed is given as constant so we can say that distance covered can be product of speed and time

So here we can use

[tex]d = v*t[/tex]

[tex]d = 30 * 1.4[/tex]

[tex]d = 42 m[/tex]

So the car will move to 42 m during the time when he apply brakes

More force to accelerate. If you push a car compared to a beach ball, which will you have to push harder for it to move? That's pretty much what the question is asking, if that helps any:)  

According to Newton's Second Law of Motion, an object with more mass require: B) more force to accelerate.

Newton's Second Law of Motion states that the acceleration of a physical object is directly proportional to the net external force acting on it and inversely proportional to its mass.

Mathematically, Newton's Second Law of Motion is given by the formula;

[tex] Acceleration = \frac {Force}{Mass} [/tex]

Basically, an object would typically require more force to accelerate when the mass of the object is large.

In conclusion, the acceleration of an object is highly dependent on the net external force acting on the object.

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A position-versus-time graph for motion with constant, nonzero acceleration forms a parabola, as the position increases at an increasing rate due to constant acceleration.

The shape of the graph for motion with constant, nonzero acceleration on a position-versus-time graph is a parabola. Acceleration - the rate of change of velocity - is constant in this scenario, implying that velocity is increasing at a constant rate. As a result, position, which is the area under the velocity versus time graph, increases at an increasing rate. This is represented graphically by a parabolic curve.

For instance, consider a car starting from rest and accelerating at a consistent rate. At the beginning of motion, the car covers a relatively small distance, resulting in a low point on the graph. As time progresses and the car accelerates, the distance covered in each subsequent time interval increases, resulting in an upward curve on the position-versus-time graph. The steepness of the curve increases with time, forming a parabolic shape.

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50 kilometers should be it

Answer:

13.89 m/s

Explanation:

Velocity=Displacement/Time

Explanation:

75 km = 75000 m

1.5 hours = 5400 sec

Applying the formula

Velocity =75000 m 5400 s = 13.89 m/s

Answer:

 Height of coffee mug = 5 cm

Explanation:

  Changing all the data given in to unit cm

              50 mm = 5 cm

              20 cm  = 20 cm

              8 m    = 800 cm

              0.1 km = 100 m = 10000 cm

Since we need to find the height of coffee mug, it's height will not be more than 10 cm.

  So 5 cm is the correct choice.

Answer:

2

Explanation:

The first person to answer was right

Given:

Time: 3.5 hrs

Velocity: 120 miles/hr

Now Distance=  Speed × Time

Now Velocity and speed have the same magnitude. Velocity being a vector quantity has a definite direction. Whereas speed is a scalar quantity,it indicates only the magnitude an doesn't define any direction.

Hence Distance = Velocity x time

Distance = 3.5 × 120 = 420 miles

The solution is attached below.